What is Narrowbanding?

Private land mobile radio (LMR) systems - including municipal government and State and local public safety systems - use blocks of radio spectrum called channels. Historically, LMR systems have used 25 kHz-wide channels. In December 2004, the Federal Communications Commission mandated that all private LMR users operating below 512 MHz move to 12.5 kHz narrowband voice channels and highly efficient data channel operations by January 1, 2013. This migration complements a National Telecommunications and Information Administration mandate for more rapid Federal agency migration to 12.5 kHz narrowband operation by January 1, 2008. The earlier Federal deadline affects State and local FCC licensees that interface or share frequencies with Federal radio systems.

Using narrowband channels will ensure that agencies take advantage of more efficient technology and, by reducing channel width, will allow additional channels to exist within the same spectrum space, as illustrated in figure 1.

Narrowband channels allow additional channels to exist in the same spectrum.

Land Mobile Radio Systems still using wideband channels as of January 1, 2013, risk the following:

• Loss of Radio Communications
• Substantial FCC Fines
• Revocation of FCC Licenses
  

Planning for the Move to Narrowband

Land Mobile Radio System Operators (both public safety and nonpublic safety) need to aggressively develop a strategy to meet narrowband deadlines to avoid cancellation of existing wideband FCC authorizations. Although the migration deadline may seem far off, the long lead time and interim deadlines make it necessary for you to plan well in advance.

Assess Current Equipment and Start Planning.

To prepare for the migration, organizations should start assessing their radio systems and planning for replacements or upgrades. They should inventory their current equipment to ascertain what can be converted to 12.5 kHz and what will need to be replaced before January 1, 2013. Most new equipment has the capability for both 25 kHz and 12.5 kHz operation because any VHF/UHF radio equipment accepted by the FCC after February 14, 1997, had to have 12.5 kHz capability. The 2.5 kHz narrowband equipment is available in both conventional analog FM and digital formats (such as Project 25), so narrowband conventional FM systems will be compliant. Local governments should develop contingency plans to accommodate system changes for both public safety and nonpublic safety systems.

Obtain New or Modified Licenses.

To move to narrowband operations, organizations must apply for new frequencies or modify existing licenses. An organization that is licensed for a 25 kHz-wide channel is not guaranteed two 12.5 kHz channels. Licensees will have to justify to the FCC why they need additional channels. Consideration of applications for new narrowband licenses will follow the same process as a new license application. As organizations migrate to narrowband operation, however, the pool of available frequencies will increase.

For More Information

Federal Communications Commission:
http://www.fcc.gov/

Direct Links to FCC Documents:
http://hraunfoss.fcc.gov/edocs_public/attachmatch/FCC-04-292A1.pdf
http://hraunfoss.fcc.gov/edocs_public/attachmatch/DOC-271692A1.pdf

 

Copyright (c) 2012 Tidewater Communications & Electronics, Inc.
All Rights Reserved